I replaced my wood spreaders on my 1983 Catalina 30 tall rig about 5 years ago. I recall there were two companies offering replacements. One required drilling the mast which I didn't want to do. The company I bought mine from were a direct replacement and all I had to do was CAREFULLY measure and drill the mounting holes on the new aluminum spreaders. Based on the condition of my old wood spreaders I didn't want the possibility of the mast coming down on someone, probably under the worst conditions.